Development Of Natural Gas Resources Research Articles

Sub-millimetric visualization and stability measurement for supercritical CO2 foams: Effect of ionic complexation on tubular and diverging flows

Development of natural gas resources as fuel for energy transition requires sustainable recovery processes with manageable amount of water used for unconventional stimulation of wellbores to protect the environment. To manage stability issues and bubble morphological alternations within the waterless fluids such as dry foams, microstructure and physiochemical properties were correlated to ionic complexation, bubble local plastic deformation (T1 event) in vicinity of constriction and elastoplastic behavior of CO2-water interface travelling from wellbore to fracture and flow back. This work presents facile sub-millimetric observation and step by step image analysis protocol for dry scCO2 foam transport and stability evaluation across the vertical view cell (tubular flow) and after constriction (diverging flow) and highlights the effect of viscoelastic components of interface on bubble plastic deformation and interfacial stability. The scCO2 foam’s microscopic structure was stabilized with (i) Zwitterionic Surfactants (ZS) and (ii) ZS-conjugated Polyelectrolyte Complex Nanoparticles (PECNP). PECNP-Surfactant scCO2 foam structure was noticeably affected by confinement ratio between the feeding tube and view cell, thus excessive lamella breakup and rearrangement of scCO2 bubbles occurred with higher rate in widening flow, which contributed to formation of less uniform dispersion of scCO2 droplets in PECNP-Surfactant scCO2 foam. However, the PECNP-Surfactant complexes residing in CO2-water lamella stabilized the deformed microstructure for significantly longer time. Bubble shape deformity was attributed to bubble elongation due to elastoplastic properties of lamella interface originated by the presence PECNP nanoparticle verified by higher dilatational elasticity at interface. Stability of deformed bubbles in pattern of PECNP-surfactant scCO2 foam with longer resistivity to lamella breakage, coalescence, and gravity drainage (up to 160 min) were compared to sudden bubble growth and expansion (after 30 min) detected for narrower distribution of smaller scCO2 bubbles stabilized in mixtures of ZS in high salinity brine (33.3 kppm). Higher resistance to morphological change (coalescence, rupture, burst) was observed for viscous lamella of PECNP-surfactant in scCO2 foam originated from higher viscosity and dilatational elasticity of lamella interface.

Influence of diapir structure on formation and distribution of overpressure in the Yinggehai Basin, South China Sea

AbstractThe Yinggehai Basin (YGH) in the South China Sea is a Cenozoic, high‐temperature, and high‐pressure basin. Exploration and development of natural gas resources in the YGH show that owing to the diapir structures make the formation pressure system is complex, overpressure characteristics are obvious, prediction is difficult, and spatial distribution is irregular, which severely restricts the development of natural gas. To evaluate the influence of diapir structures on the formation and distribution of overpressure, we compared and analyzed the ancient and modern geothermal temperatures, organic matter maturity, clay mineral evolution, burial depth, and pressure coefficient in the diapir and nondiapir zones of the YGH. The results showed that of the diapir structures in the YGH occurred in the following order: Uplift–spiking–piercing–depositing. The Dongfang area is dominated by low‐amplitude turtle‐back diapir structures with weak energy, whereas the Ledong area is dominated by high‐amplitude spiked diapir structures with strong energy, both of which pressurize the upper formation. The Changnan area is dominated by high‐amplitude pierced/depositing diapirs with strong energy, which can relieve pressure. The influence of the diapir and its associated structures on the formation of overpressure can be attributed to the transport of the diapir body and the associated fault‐fracture system and the local thermal effect caused by the upwelling of hot fluids. Under the influence of the diapir structure, the overpressure top surface of the basin was shallower. According to the degree of influence and intensity of the diapir structure, variations in formation pressure coefficient with depth can be divided into four evolution modes: constant pressure, slow pressurization, “Z” pressurization, and “S” pressurization types. This study provides some guidance and references for the identification and accurate prediction of the overpressure formation mechanism in basins containing diapirs, and helps in formulating efficient drilling and production plans.

Drilling and completion technologies for deep carbonate rocks in the Sichuan Basin: Practices and prospects

The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata. The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties, such as multiple pressure systems, poor drillability, ultra-high pressure, ultra-high temperature and high sulfur content, which bring great challenges to drilling and completion engineering. In order to ensure the smooth exploration and development of deep carbonate oil and gas resources in the Sichuan Basin, the overall concept of combining field practice and technological research is followed. During the 13th Five-Year Plan, a batch of ultra-deep wells (well depth about 8000 m) have been drilled fast and safely (such as Well SYX133 in the Shuangyushi structure), and great progresses have been achieved in the experimental research of the support technologies in drilling and completion of deep and ultra-deep wells. And the achievements are as follows. First, the optimization of non-standard well structure, combined with the application of precisely managed pressure drilling technology and under-pressure plugging technology, lays a foundation for the optimized fast drilling and the safe reaching of geological targets. Second, a high-efficiency customized PDC drill bit is comprehensively optimized, popularized and applied, which effectively improves the average rate of penetration (ROP) in difficult-to-drill formations. Third, the development and application of drilling fluids (e.g. being resistant to high temperature of 200 °C and anti-composite brine) and active under-pressure plugging technology effectively reduces downhole complexities while drilling the complex formations, such as high temperature and high pressure brine and circulation loss. Fourth, when precisely managed pressure drilling and precisely managed pressure cementing methods are applied in the strata with a narrow density window, multiple pressure systems and pressure sensitivity, the average drilling and completion fluid loss is reduced by more than 90%, and the complexity treatment time is cut down by more than 85%, and the cementing quality pass rate is increased by more than 20%. Fifth, the integrated application of ROP improvement technologies and tools (e.g. air drilling) results in a great reduction of drilling cycle and cost. It is concluded that the experimental research achievements provide basic support for the fast development of natural gas resources in the Anyue Gas Field, Sichuan Basin, and the great discovery of the Permian and Devonian natural gas resources in the northwestern Sichuan Basin. What's more, in order to adapt to the development of the deep natural gas (over 9000 m) in the Sichuan Basin during the 14th Five-Year Plan, it is necessary to speed up researches on drilling and completion technologies in nine aspects, e.g. high-temperature downhole tools and working fluid.

In-situ observation for natural gas hydrate in porous medium: Water performance and formation characteristic

Extensive efforts have been made regarding gas hydrate sample reconstruction in the laboratory for a better understanding and development of natural gas resources. Magnetic resonance imaging (MRI) is a useful method for directly observing the reconstruction of methane hydrate, yet relevant studies remain limited. In this study, a 9.4-T 400-MHz MRI instrument was employed to investigate CH4 hydrate formation in porous media involving various initial water saturation levels and sand diameters. Pressure histories and MRI signal variations were monitored to discuss the process of CH4 hydrate growth, and the three main formation stages of induction, rapid growth, and slow formation were determined. Furthermore, the liquid water performance in MRI micro-images was analyzed to predict the characteristics of CH4 hydrate formation. The results indicated that CH4 hydrate formed in a spatially and temporally random manner and that pore plugging occurred owing to the residual water encased in grown hydrate. Additionally, phase saturations, water conversion percentages, and formation rates were defined to evaluate the effect of sand diameter and initial water saturation on CH4 hydrate formation. With the reduction in the diameter of quartz glass beads from 400 μm to 100 μm, the average hydrate formation rate increased from 0.0010 min−1 to 0.0034 min−1, respectively. When the initial water saturation decreased to the optimized value (0.22 in this study), the water conversion percentage and hydrate saturation increased.

NATURAL GAS POTENTIAL OF LAND FORMATION IN UKRAINE

The analysis of the potential of natural gas resources of gas prospective shale formations in the main oil and gas basins of Ukraine, that is of Eastern, Western, Southern ones. On the basis of economic and mathematical modeling of geological and economic characteristics of shale formations, from which successful shale gas mining is currently being carried out in the world, correlation-regressive dependencies have been established. They allow to carry out a predicted estimation of the gas content, the initial rate of gas extraction wells, the marginal cost limit, at which a break-even production of natural gas from shale formations is possible. Using these dependencies, an analysis of the resource potential of slate formations has been carried out and it has been established that in the Eastern region stratigraphic complexes with promising shale formations are included: Devonian deposits - Upper Devonian (Famensian tier); coal deposits - Lower Carboniferous Complex (Tourney, Viseu, Serpukhov Tiers); middle-complex complex (Bashkir and Moscow tiers); Carboniferous complex (Kasimovsky and Gzhel tiers). Yevgenivsko-Druzhelyubivsk, Mirgorod-Livensk, Borkivsk-Velikzagorivsk and Zachipelsk-Livensk areas are the most investments-attractive in the prospects for shale gas extraction in the Eastern region. In the Western region, prospective stratigraphic complexes include deposits of the Cambrian, Silurian and Oligocene-Miocene age. The most investment attractive for shale gas extraction in the Western region is Davydivsky, Rava-Russkaya, East-Lishinskaya and Oleska districts. In the Southern region, perspective shale gas extraction is the deposits of the Middle Jurassic, the upper part of the Visean tier and the lower part of the Serpukhov tier of the carbon fiber of the Pre-Dobrug Trough. The results obtained can serve as a basis for investors to select priority objects for the development of natural gas resources from shale formations in Ukraine.

PUBLIC-PRIVATE PARTNERSHIP IN THE DEVELOPMENT OF SHALE GAS RESOURCES IN UKRAINE

The article considers the possibilities of using the institution of public-private partnership in the development of natural gas resources from shale formations. The economic expediency of using public-private partnership in the development of these resources is due to the need to overcome deficiencies in the existing system of nature management and the use of an effective institute of civil ownership of natural resources. Features of public-private partnership in the development of natural resources, the possibility of applying various types of transactions, methodical approaches to the formation of information necessary for their conclusion, relating to the content of gas in slate formations, forecasting the productivity of wells, the marginal cost limits, at which a profitable extraction of shale gas is possible , capitalization of shale gas resources. The criteria for the selection of the most promising zones of "sweeps spots" (sweet places) are established on significant areas of their distribution, which is the main task of exploration for the purpose of exploration, exploration and extraction of shale gas. It was investigated that the institutions of financing shale gas extraction are important in concluding public-private partnership agreements, the key role of which is the capitalization of natural resources - the process of conversion of factors of production into capital. The method of capitalization of shale gas resources in the subsoil is described, which will enable application of the concept of project investment.
 The directions of perfection of the institute of public-private partnership during development of shale gas resources are determined.
 Key words: public-private partnership, shale gas, characteristics of shale formations, gas content, wells productivity, the cost of unprofitable shale gas extraction, investment efficiency, capitalization of shale gas resources.

Does methane pose significant health and public safety hazards?—A review

It has been suggested by some that methane contamination of water wells is the main negative consequence of the development of natural gas resources. Concurrently, speculation in academic white papers and in the press that methane may be toxic has resulted in public concern. In northern Pennsylvania, methane being released from groundwater and entering homes (so-called stray gas) has become a focus of this concern. This phenomenon was widespread decades before shale gas development was initiated. This paper reviews the available literature on the safety and health hazards associated with natural gas. It concludes that the risks to homeowners are highest from flash fires occurring in methane oxygen gas clouds at relatively low methane concentrations collecting in poorly ventilated, confined areas of houses such as basements. Such risks can be mitigated effectively and in most cases at minimal cost. Methane can result in death from hypoxia (lack of oxygen) but only at methane levels in the air of more than 60%, which are unlikely to develop except under exceptional circumstances. There is no evidence that low to moderate levels of exposure to methane in air have any toxic effect on humans, and evidence for such effects at very high levels (already fatal because of hypoxia) is equivocal. It seems likely that methane at concentrations at least as high as 2.5% may well have positive health benefits for some diseases.

Study on the Sustainable Development of Natural Gas Resources in China

Study on the Sustainable Development of Natural Gas Resources in China

Reprint of: Two-year survey of earthquakes and injection/production wells in the Eagle Ford Shale, Texas, prior to the [formula omitted] 20 October 2011 earthquake

Between November 2009 and September 2011 the EarthScope USArray program deployed ∼25 temporary seismograph stations on a 70-km grid in south-central Texas between 27°N–31°N and 96°W–101°W. This area includes the Eagle Ford Shale. For decades this geographic region has produced gas and oil from other strata using conventional methods, but recent developments in hydrofracturing technology has allowed extensive development of natural gas resources from within the Eagle Ford. Our study surveys small-magnitude seismic events and evaluates their correlation with fluid extraction and injection in the Eagle Ford, identifying and locating 62 probable earthquakes, including 58 not reported by the U.S. Geological Survey. The 62 probable earthquakes occur singly or in clusters at 14 foci; of these foci, two were situated near wells injecting recently increased volumes of water; eight were situated near wells extracting recently increased volumes of oil and/or water; and four were not situated near wells reporting significant injection/extraction increases. Thus in this region, while the majority of small earthquakes may be triggered/induced by human activity, they are more often associated with fluid extraction than with injection. We also investigated the MW4.8 20 October 2011 Fashing earthquake—the largest historically reported earthquake in south-central Texas—that occurred two weeks after the removal of the temporary USArray stations. A field study indicated that the highest-intensity (MMI VI) region was about 10 km south of 2010–2011 foreshock activity, and that there were no high-volume injection wells within 20 km of the MMI V–VI region or the foreshocks. However, the 20 October 2011 earthquake did coincide with a significant increase in oil/water extraction volumes at wells within the MMI V–VI region, and this was also true for previous earthquakes felt at Fashing in 1973 and 1983. In contrast, our study found significant increases in injection prior to an mbLG3.6 20 July 1991 earthquake near Falls City, Texas. Thus the Eagle Ford geographic region, with seismic activity associated both with extraction and injection, appears to be more complex than the Barnett Shale of northeast Texas, where a similar survey found possible correlations only with fluid injection.

Quantifying the potential effects of high-volume water extractions on water resources during natural gas development: Marcellus Shale, NY

Abstract Study region The Marcellus Shale, New York State, USA. Study focus Development of natural gas resources within the Marcellus Shale will require large volumes of water if high-volume hydraulic fracturing expands into New York State. Although this region has ample fresh water resources, it is necessary to explore the response of hydraulically connected groundwater and surface water systems to large withdrawals. Because such effects would not be apparent from a typical water budget approach, this study applied groundwater flow modelling under scenarios of high-volume water withdrawals. Emphasis on water quantity, in contrast with other lines of research concerning water quality, introduced an important perspective to this controversial topic. New hydrological insights for the region The potential effects of the withdrawal scenarios on both the water table and stream discharge were quantified. Based on these impact results, locations in the aquifer and stream networks were identified, which demonstrate particular vulnerability to increased withdrawals and their distribution. These are the locations of importance for planners and regulators who oversee water permitting, to reach a sustainable management of the water resources under changing conditions of energy and corresponding water demand.

Estimating the Consumptive Use Costs of Shale Natural Gas Extraction on Pennsylvania Roadways

The development of natural gas resources in the Marcellus Shale formation has progressed rapidly in the last several years, particularly in the Commonwealth of Pennsylvania. These activities require many heavy truck trips for equipment and materials, which can damage state and local roads that were not designed for high volumes of heavy truck traffic. For state transportation agencies, one measure of costs of shale gas development is the potential degradation of roadways resulting from shale gas development. This technical note, provides a first-order an estimate of roadway consumptive use costs of additional heavy truck traffic on Pennsylvania state-maintained roadways from Marcellus Shale natural gas development in 201, estimated at 1 about $13,000–$23,000 per well for all state roadway types, or $5,000–$10,000 per well if state roads with the lowest traffic volumes are excluded. This initial estimate of costs, is based on data on the distribution of well activity and roadway type in Pennsylvania, estimates for the number of heavy truck trips to construct and operate a single well, the corresponding equivalent single-axle loadings, and estimates of roadway life and reconstruction costs by roadway maintenance class in Pennsylvania.

Industry/Research Collaboration Advances Oil and Gas Technologies

R&D on Campus - Universities are working hard to anticipate the demand for new technologies and techniques as oil and gas exploration delves into deeper waters, harsher climates, and unconventional fields. Numerous universities are teaming up with the industry on projects such as modeling software, heavy oil technologies, fines migration, drilling technologies, and foam to enhance oil recovery and production. Through these research collaborations, more efficient methods are being developed to meet the increasing global consumption of oil and gas. Petroleum Engineering Department, Colorado School of Mines, US The Petroleum Engineering Department at the Colorado School of Mines has a large undergraduate and graduate enrollment and a healthy mix of multidisciplinary research efforts including the Unconventional Natural Gas and Oil Institute; the Marathon Center of Excellence for Reservoir Studies; the Fracturing, Acidizing, Stimulation Technology Consortium; the Energy Modeling Group; the Unconventional Reservoir Engineering Project; and the Physics of Organics, Carbonates, Clays, Sands, and Shales Consortium. One area of focus is the Routes to Sustainability for Natural Gas Development and Water and Air Resources project in the Rocky Mountain Region. For this project, the Petroleum Engineering and the Civil and Environmental Engineering departments are working with their sister school, the University of Colorado at Boulder, and seven other institutions in a Sustainability Research Network (SRN) funded by a 5-year grant from the US National Science Foundation. The mission of the SRN is to provide a logical, science-based framework for evaluating environmental, economic, and social trade-offs between the development of natural gas resources in the Rocky Mountain Region and the protection of water and air resources. The SRN plans to give the results of these evaluations to the public in a way that will improve policies and regulations governing oil and gas exploration. “Our goal is to find the balance between maximizing the development of natural gas and oil resources for the benefits of short-term reduction of CO2 emissions from power generation and transportation, national energy independence, and national job growth, while minimizing damage to water and air resources and risks to human health,” said Joseph N. Ryan, faculty director of the research project.

Two-year survey of earthquakes and injection/production wells in the Eagle Ford Shale, Texas, prior to the [formula omitted] 20 October 2011 earthquake

Between November 2009 and September 2011 the EarthScope USArray program deployed ∼25 temporary seismograph stations on a 70-km grid in south-central Texas between 27°N–31°N and 96°W–101°W. This area includes the Eagle Ford Shale. For decades this geographic region has produced gas and oil from other strata using conventional methods, but recent developments in hydrofracturing technology has allowed extensive development of natural gas resources from within the Eagle Ford. Our study surveys small-magnitude seismic events and evaluates their correlation with fluid extraction and injection in the Eagle Ford, identifying and locating 62 probable earthquakes, including 58 not reported by the U.S. Geological Survey. The 62 probable earthquakes occur singly or in clusters at 14 foci; of these foci, two were situated near wells injecting recently increased volumes of water; eight were situated near wells extracting recently increased volumes of oil and/or water; and four were not situated near wells reporting significant injection/extraction increases. Thus in this region, while the majority of small earthquakes may be triggered/induced by human activity, they are more often associated with fluid extraction than with injection. We also investigated the MW4.8 20 October 2011 Fashing earthquake—the largest historically reported earthquake in south-central Texas—that occurred two weeks after the removal of the temporary USArray stations. A field study indicated that the highest-intensity (MMI VI) region was about 10 km south of 2010–2011 foreshock activity, and that there were no high-volume injection wells within 20 km of the MMI V–VI region or the foreshocks. However, the 20 October 2011 earthquake did coincide with a significant increase in oil/water extraction volumes at wells within the MMI V–VI region, and this was also true for previous earthquakes felt at Fashing in 1973 and 1983. In contrast, our study found significant increases in injection prior to an mbLG3.6 20 July 1991 earthquake near Falls City, Texas. Thus the Eagle Ford geographic region, with seismic activity associated both with extraction and injection, appears to be more complex than the Barnett Shale of northeast Texas, where a similar survey found possible correlations only with fluid injection.

Ozone Impacts of Natural Gas Development in the Haynesville Shale

The Haynesville Shale is a subsurface rock formation located beneath the Northeast Texas/Northwest Louisiana border near Shreveport. This formation is estimated to contain very large recoverable reserves of natural gas, and during the two years since the drilling of the first highly productive wells in 2008, has been the focus of intensive leasing and exploration activity. The development of natural gas resources within the Haynesville Shale is likely to be economically important but may also generate significant emissions of ozone precursors. Using well production data from state regulatory agencies and a review of the available literature, projections of future year Haynesville Shale natural gas production were derived for 2009-2020 for three scenarios corresponding to limited, moderate, and aggressive development. These production estimates were then used to develop an emission inventory for each of the three scenarios. Photochemical modeling of the year 2012 showed increases in 2012 8-h ozone design values of up to 5 ppb within Northeast Texas and Northwest Louisiana resulting from development in the Haynesville Shale. Ozone increases due to Haynesville Shale emissions can affect regions outside Northeast Texas and Northwest Louisiana due to ozone transport. This study evaluates only near-term ozone impacts, but the emission inventory projections indicate that Haynesville emissions may be expected to increase through 2020.

Marginal costs of undiscovered natural gas resources in the United States with possible application to world oil and gas resources

The Mineral Resources Institute of the Colorado School of Mines is completing a project sponsored jointly by the Gas Research Institute and the Electric Power Research Institute to assess the cost of development of natural gas resources in the United States. The project has as its objective the development of a method and subsequent calculation of costs which might be anticipated in the discovery and development of the undiscovered natural gas resources of the nation. Costs are expressed in constant dollars and are intended to provide a measure of the relative costs which would be encountered in various, regions and at various depths. The project work was supported by the development of a model for calculation of full marginal costs of resource discovery and development by Operational Economics, Inc. This paper summarizes the data sources, methodology, and results of the analyses performed, as well as some interpretations of those results. Additionally, the paper includes some possible applications of the procedures and the models to the estimation of the costs of development of the oil resources of the United States and of the oil and gas resources of the world.